Beam Steerer

The beam steerer mirrors #1 and #2 are flats that steer the telescope beam to one of the three NIRI camera lenses (#1) and then onto the near-IR array detector (#2). The camera lenses provide f/6, f/14 and f/32 beams for wide-field, medium-field non-AO (tip/tilt) and high-resolution AO imaging modes, respectively. The photo below shows the location of the beam steerer mirrors which are enclosed in a housing for protection and extra light baffling. Also shown in this photo is the pupil mask/filter wheel and the f/14 and f/32 camera optics barrels. The f/6 optics are located below the optical table as is the near-IR array detector. Since the camera lenses are fixed, the beam steerer mirrors rotate to direct the beam in one of three possible directions.